Health Information

Guides you through decision to have triple or quadruple test to look for Down syndrome and birth defects. Discusses what the tests look for. Covers benefits and risks. Includes interactive tool to help you make your decision.

Guides you through decision to have triple or quadruple test to look for Down syndrome and birth defects. Discusses what the tests look for. Covers benefits and risks. Includes interactive tool to help you make your decision.

Pregnancy: Should I Have Screening Tests for Birth Defects?

You may want to have a say in this decision, or you may simply want to follow your doctor's recommendation. Either way, this information will help you understand what your choices are so that you can talk to your doctor about them.

Key points to remember

Testing for birth defects means that you may find out that your baby has a serious problem. So it's important to think about what that would mean to you and your partner. Would the news that your baby has a birth defect change your parenting plans? If, for example, you know that you would continue your pregnancy even with a birth defect, you might decide not to have any tests for birth defects.

Screening tests can't be used to diagnose a birth defect. They only
estimate the chance that your baby has a birth defect.
If one of these tests shows a higher-than-normal chance of a birth defect, you
would then decide whether to have a diagnostic test—such as chorionic villus sampling (CVS) in the first trimester or
amniocentesis in the second trimester—to find out for sure if there is a
problem.

Screening tests for birth defects include blood tests and a certain type of ultrasound. Depending on the type of screening you have, the test can help your doctor estimate
the chance that your
baby may have
Down syndrome, neural tube defects, or certain rare genetic problems.
The blood tests are used to look for the amount of certain substances in your blood. The doctor uses an ultrasound to look for certain changes in your baby.

Other things are considered along with the test results to estimate the chance
of a problem. For example, your doctor will look at your age, weight, and race, and
how far along your pregnancy is.

If one of these tests shows a higher-than-normal chance of a birth defect, you
would then decide whether to have a diagnostic test—chorionic villus sampling (CVS) or
amniocentesis. These tests can show for sure if there is a
problem. Diagnostic tests involve taking some of the baby's cells to look at the genes and chromosomes. But diagnostic tests have a small risk of causing a miscarriage.

The American College of Obstetricians and Gynecologists
recommends that all women be offered a screening test for Down syndrome. The
risk of having a baby with a genetic condition increases as a woman gets older.

If you choose to have a test for birth defects, you may want to talk with a genetic counselor. He or she can talk with you about your test options and about the reasons to have or not have tests.

Screening tests may be done in the first or second trimester of pregnancy.

First trimester screening tests

First trimester screening tests let you find out about Down syndrome early in your pregnancy—between 10 and 13 weeks. But they aren't used to look for neural tube defects. This screening combines the results of two tests:

Nuchal translucency test. This test uses ultrasound to measure the thickness of the area at the back of the baby's neck. An increase in the thickness can be an early sign of Down syndrome. The test is not available everywhere, because a doctor must have special training to do it.

First-trimester blood tests. These tests measure the amounts of two substances in your blood: beta human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein A (PAPP-A). High levels of beta-hCG and low levels of PAPP-A may be related to certain birth defects.

A newer screening test—called cell free fetal DNA—looks at fetal DNA in a pregnant woman's blood. It can be used to look for Down syndrome and trisomy 18. It also may find trisomy 13, which causes intellectual disability and heart defects, among other problems. This test is an option for women who are at high risk for having a baby with certain genetic conditions. But it can't help find other birth defects, such as neural tube defects. It's not used as a general screening test. And it's not available everywhere.

Second trimester screening tests

Second-trimester screening—done between 15 and 20 weeks of pregnancy—can be used to look for Down syndrome and neural tube defects.

Maternal serum triple
screen. Sometimes called the triple test, it measures the amounts
of three substances in a pregnant woman's blood:

Alpha-fetoprotein (AFP)

Human chorionic gonadotropin (hCG)

Estriol (uE3)

Quadruple (or quad) test.
It combines the triple screen and a test for the
hormone inhibin A, which is produced by the fetus and the placenta. The quad test is a little more accurate than the triple screen. But it might not be available everywhere.

Integrated screening test. It combines the results of the first-trimester tests with those of the triple or quad screening. You would get the results after the second-trimester test is done.

Ultrasound. Doctors use ultrasound between 18 and 20 weeks. They look at a fetus's organs and other features that may be signs of conditions such as Down syndrome, neural tube defects, or heart problems.

First trimester screening

First-trimester screening (nuchal translucency combined with blood tests) correctly finds Down syndrome in 82 to 87 out of 100 fetuses that have it. This also means that these tests miss it in 13 to 18 out of 100 fetuses.1

Ultrasound

An ultrasound can find
neural tube defects up to 99 out of 100 times.2 It won't find these problems 1 time out of 100. But
ultrasound isn't as good at finding
Down syndrome or genetic diseases.

Triple or quad screening

The triple or quad screen finds 80 out of 100 fetuses with
neural tube defects, such as spina bifida, and about 90 out of 100 with
anencephaly.2 The test misses
20 out of 100 fetuses with spina bifida and 10 out of 100 with
anencephaly.

The quad test finds
Down syndrome almost 81 out of 100 times. It doesn't
find it 19 out of 100 times.3 The quad test is more
likely to find Down syndrome and may be less likely to be
false-positive than the triple screen.

Integrated screening

The integrated screening test (first-trimester tests plus the quad screening in the second trimester) correctly finds Down syndrome in about 95 out of 100 fetuses who have it. This also means that the test misses Down syndrome in 5 out of 100 fetuses.1

Normal results tell you that there is no need for more tests
unless you have another concern, such as a known genetic disease in your
family.

Positive results tell you that
there is a higher-than-average chance of a birth defect. You will be offered a diagnostic test, such as chorionic villus sampling (CVS) or amniocentesis, to find out for sure if there is a problem.

Or you may decide not to have any more tests.

If a birth defect is found, you decide where to go from
there. You may choose to learn all you can about raising a child with Down
syndrome or a birth defect. Or you may decide to end the pregnancy.

With the blood tests, there is little or no physical
risk. A fetal ultrasound has no known risks.

Having tests may make you worry. There
is a chance that the test could show that there's a problem when there isn't
one. This is called a
false-positive test result. Or the test could miss a problem. This is a false-negative test result.

A positive result (meaning there could be a problem) could lead you to have a diagnostic test, which has a small risk of causing a miscarriage.

But most women have normal test results. Even when the test result is positive,
most pregnancies turn out to have no problems.

Personal stories about deciding to have a screening test for birth defects

These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.

I know that
I'm at a higher risk of having a baby with Down syndrome because of my age.
My husband and I don't have any risk factors for having a child with other
birth defects. If the screening tests weren't available, I would probably have
an amniocentesis even though it has some risks. But since I can have the
screening tests, I've decided to start with that and then make a decision about
amniocentesis based on the results.

Rachel, age 37

I'm not
really worried about things like birth defects that might or might not happen.
I don't have any risk factors for having a baby with a birth defect. And I know
a lot of women who have had amniocentesis and other tests who spent a lot of
time worrying, only to have healthy, normal babies. I feel like the best thing
I can do is take good care of myself, stay alert for any signs that there is a
problem, and enjoy my pregnancy.

Yvonne, age 31

My neighbor
had her first baby at our rural community hospital. The baby had spina bifida,
and they rushed her by ambulance to the nearest city and then by helicopter to
a center that treats babies with this problem. My neighbor had to follow her
later on and so was away from her baby at a really traumatic time. It was such
a scary experience for her. I am definitely going to have the screening tests
and find out my risk of having a baby that needs special care so we can plan
ahead.

Candace, age
26

My husband and I want to have the most
definitive information possible to make decisions about my pregnancy. So we are
going to start with the chorionic villus sampling. I know it's a little more
risky, but we feel like we need as much information as early as we can get it.
It took us a little longer than we expected to become pregnant. If there is any
chance that the fetus has a birth defect, we want to know that as soon as we
can so we can make the best decision for us about whether to continue this
pregnancy or end it and give ourselves a chance to try again.

Elena, age
37

What matters most to you?

Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.

You may want to have a say in this decision, or you may simply want to follow your doctor's recommendation. Either way, this information will help you understand what your choices are so that you can talk to your doctor about them.

Pregnancy: Should I Have Screening Tests for Birth Defects?

Here's a record of your answers. You can use it to talk with your doctor or loved ones about your decision.

Get the facts

Compare your options

What matters most to you?

Where are you leaning now?

What else do you need to make your decision?

1. Get the Facts

Your options

Have a screening test to find out the chance that your baby has a birth defect.

Don't have a screening test. You may decide not to have any tests. Or, you may want to have a diagnostic test—which shows
for sure if there is a birth defect.

Key points to remember

Testing for birth defects means that you may find out that your baby has a serious problem. So it's important to think about what that would mean to you and your partner. Would the news that your baby has a birth defect change your parenting plans? If, for example, you know that you would continue your pregnancy even with a birth defect, you might decide not to have any tests for birth defects.

Screening tests can't be used to diagnose a birth defect. They only
estimate the chance that your baby has a birth defect.
If one of these tests shows a higher-than-normal chance of a birth defect, you
would then decide whether to have a diagnostic test—such as chorionic villus sampling (CVS) in the first trimester or
amniocentesis in the second trimester—to find out for sure if there is a
problem.

If you plan to have a diagnostic test such as CVS or amniocentesis, you can skip
screening tests.

Screening tests have less risk than diagnostic tests.

Screening tests for birth defects can't find every problem a baby could have.

A birth defects test can cost a lot. Check to see if your insurance plan will cover it.

FAQs

What are screening tests?

Screening tests for birth defects include blood tests and a certain type of ultrasound. Depending on the type of screening you have, the test can help your doctor estimate
the chance that your
baby may have
Down syndrome, neural tube defects, or certain rare genetic problems.
The blood tests are used to look for the amount of certain substances in your blood. The doctor uses an ultrasound to look for certain changes in your baby.

Other things are considered along with the test results to estimate the chance
of a problem. For example, your doctor will look at your age, weight, and race, and
how far along your pregnancy is.

If one of these tests shows a higher-than-normal chance of a birth defect, you
would then decide whether to have a diagnostic test—chorionic villus sampling (CVS) or
amniocentesis. These tests can show for sure if there is a
problem. Diagnostic tests involve taking some of the baby's cells to look at the genes and chromosomes. But diagnostic tests have a small risk of causing a miscarriage.

The American College of Obstetricians and Gynecologists
recommends that all women be offered a screening test for Down syndrome. The
risk of having a baby with a genetic condition increases as a woman gets older.

If you choose to have a test for birth defects, you may want to talk with a genetic counselor. He or she can talk with you about your test options and about the reasons to have or not have tests.

Screening tests may be done in the first or second trimester of pregnancy.

First trimester screening tests

First trimester screening tests let you find out about Down syndrome early in your pregnancy—between 10 and 13 weeks. But they aren't used to look for neural tube defects. This screening combines the results of two tests:

Nuchal translucency test. This test uses ultrasound to measure the thickness of the area at the back of the baby's neck. An increase in the thickness can be an early sign of Down syndrome. The test is not available everywhere, because a doctor must have special training to do it.

First-trimester blood tests. These tests measure the amounts of two substances in your blood: beta human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein A (PAPP-A). High levels of beta-hCG and low levels of PAPP-A may be related to certain birth defects.

A newer screening test—called cell free fetal DNA—looks at fetal DNA in a pregnant woman's blood. It can be used to look for Down syndrome and trisomy 18. It also may find trisomy 13, which causes intellectual disability and heart defects, among other problems. This test is an option for women who are at high risk for having a baby with certain genetic conditions. But it can't help find other birth defects, such as neural tube defects. It's not used as a general screening test. And it's not available everywhere.

Second trimester screening tests

Second-trimester screening—done between 15 and 20 weeks of pregnancy—can be used to look for Down syndrome and neural tube defects.

Maternal serum triple
screen. Sometimes called the triple test, it measures the amounts
of three substances in a pregnant woman's blood:

Alpha-fetoprotein (AFP)

Human chorionic gonadotropin (hCG)

Estriol (uE3)

Quadruple (or quad) test.
It combines the triple screen and a test for the
hormone inhibin A, which is produced by the fetus and the placenta. The quad test is a little more accurate than the triple screen. But it might not be available everywhere.

Integrated screening test. It combines the results of the first-trimester tests with those of the triple or quad screening. You would get the results after the second-trimester test is done.

Ultrasound. Doctors use ultrasound between 18 and 20 weeks. They look at a fetus's organs and other features that may be signs of conditions such as Down syndrome, neural tube defects, or heart problems.

How well do these tests work to find birth defects?

First trimester screening

First-trimester screening (nuchal translucency combined with blood tests) correctly finds Down syndrome in 82 to 87 out of 100 fetuses that have it. This also means that these tests miss it in 13 to 18 out of 100 fetuses.1

Ultrasound

An ultrasound can find
neural tube defects up to 99 out of 100 times.2 It won't find these problems 1 time out of 100. But
ultrasound isn't as good at finding
Down syndrome or genetic diseases.

Triple or quad screening

The triple or quad screen finds 80 out of 100 fetuses with
neural tube defects, such as spina bifida, and about 90 out of 100 with
anencephaly.2 The test misses
20 out of 100 fetuses with spina bifida and 10 out of 100 with
anencephaly.

The quad test finds
Down syndrome almost 81 out of 100 times. It doesn't
find it 19 out of 100 times.3 The quad test is more
likely to find Down syndrome and may be less likely to be
false-positive than the triple screen.

Integrated screening

The integrated screening test (first-trimester tests plus the quad screening in the second trimester) correctly finds Down syndrome in about 95 out of 100 fetuses who have it. This also means that the test misses Down syndrome in 5 out of 100 fetuses.1

What's next after you get the test results?

Normal results tell you that there is no need for more tests
unless you have another concern, such as a known genetic disease in your
family.

Positive results tell you that
there is a higher-than-average chance of a birth defect. You will be offered a diagnostic test, such as chorionic villus sampling (CVS) or amniocentesis, to find out for sure if there is a problem.

Or you may decide not to have any more tests.

If a birth defect is found, you decide where to go from
there. You may choose to learn all you can about raising a child with Down
syndrome or a birth defect. Or you may decide to end the pregnancy.

What are the risks of having a screening test?

With the blood tests, there is little or no physical
risk. A fetal ultrasound has no known risks.

Having tests may make you worry. There
is a chance that the test could show that there's a problem when there isn't
one. This is called a
false-positive test result. Or the test could miss a problem. This is a false-negative test result.

A positive result (meaning there could be a problem) could lead you to have a diagnostic test, which has a small risk of causing a miscarriage.

But most women have normal test results. Even when the test result is positive,
most pregnancies turn out to have no problems.

What are the risks of NOT having a screening test?

If you don't have a screening test to diagnose a birth
defect, your baby could have a problem that you don't find out about until
birth.

The birth could be higher-risk for the baby
if your doctor is not expecting a newborn with health problems.

You
could give birth in a hospital that does not have a neonatal intensive care
unit (NICU) for sick newborns.

A fetus with a rare, severe birth defect
sometimes dies before delivery.

You might not be emotionally ready
for a sick baby or one with
Down syndrome.

You might change your birth
or parenting plans if you knew your fetus had a serious problem.

2. Compare your options

Have a screening
test

Don't have screening

What is usually involved?

You have a blood test, an ultrasound, or both.

Based on the result, you decide whether to have more tests, such
as
chorionic villus sampling (CVS) or amniocentesis.

You may decide not to have any tests for birth
defects.

You may decide to skip screening tests and have CVS or amniocentesis. This can find out for sure if there is
a problem.

What are the benefits?

You can find out if there is a chance of a problem with your
fetus.

The tests are good at finding a problem if there is
one.

You may have peace of mind if the test shows no increased chance of a problem.

You won't have the worry of a test that may show a problem when
there isn't one.

You can avoid the cost of a screening test and go right to CVS or
amniocentesis to find out for sure if there is a problem.

What are the risks and side effects?

The tests have a chance of showing a problem when there
isn't one. This could make you worry.

The tests can't diagnose a
problem, so you might need other tests if the screening test is
positive.

If you don't have any tests for birth defects, your baby could
have a problem that you don't find out about until birth.

CVS and amniocentesis have about a 1 out of 400 risk of
causing a miscarriage.4 They don't lead
to a miscarriage 399 out of 400 times. The tests also have a risk of bleeding and
infection.

Personal stories

Are you interested in what others decided to do? Many people have faced this decision. These
personal stories
may help you decide.

Personal stories about deciding to have a screening test for birth defects

These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.

"I know that I'm at a higher risk of having a baby with Down syndrome because of my age. My husband and I don't have any risk factors for having a child with other birth defects. If the screening tests weren't available, I would probably have an amniocentesis even though it has some risks. But since I can have the screening tests, I've decided to start with that and then make a decision about amniocentesis based on the results."

— Rachel, age 37

"I'm not really worried about things like birth defects that might or might not happen. I don't have any risk factors for having a baby with a birth defect. And I know a lot of women who have had amniocentesis and other tests who spent a lot of time worrying, only to have healthy, normal babies. I feel like the best thing I can do is take good care of myself, stay alert for any signs that there is a problem, and enjoy my pregnancy."

— Yvonne, age 31

"My neighbor had her first baby at our rural community hospital. The baby had spina bifida, and they rushed her by ambulance to the nearest city and then by helicopter to a center that treats babies with this problem. My neighbor had to follow her later on and so was away from her baby at a really traumatic time. It was such a scary experience for her. I am definitely going to have the screening tests and find out my risk of having a baby that needs special care so we can plan ahead."

— Candace, age
26

"My husband and I want to have the most definitive information possible to make decisions about my pregnancy. So we are going to start with the chorionic villus sampling. I know it's a little more risky, but we feel like we need as much information as early as we can get it. It took us a little longer than we expected to become pregnant. If there is any chance that the fetus has a birth defect, we want to know that as soon as we can so we can make the best decision for us about whether to continue this pregnancy or end it and give ourselves a chance to try again."

— Elena, age
37

"Even though I wouldn't choose to end my pregnancy if I found out the baby had a birth defect, I still want to know ahead of time if possible. I would like to have the time to learn as much as I could about what to expect, where to have the baby, and what sort of special care it might need after it is born."

— Deena, age 32

3. What matters most to you?

Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.

Note: The "printer friendly" document will not contain all the information available in the online document some Information (e.g. cross-references to other topics, definitions or medical illustrations) is only available in the online version.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use.
How this information was developed to help you make better health decisions.